Improved sealing assembly for refrigerator cabinets and the like with a profile made of plastic material

ABSTRACT

Sealing assembly comprising a bellows-scal gasket ( 20 ) and a profile ( 1 ) with a base ( 3 ) provided, at opposite ends, with sealing strips ( 4, 15 ) and a groove ( 23 ) for a replacement of the bellows-seal gasket ( 20 ); the profile ( 1 ) has at least one side branch ( 7 ) terminating in a grooved scat ( 9 ) with a C-shaped cross-section for receiving an edge ( 28 ) of an inner door panel ( 31 ) against which a sealing strip ( 2 ) provided at the end of the grooved seat ( 9 ) is pressed under the action of elastic return of the side branch ( 7 ); the inner door panel ( 31 ) is bend with a radius that ensures an optimal contact with one of the sealing strips ( 15 ) of the base ( 3 ) of the profile ( 1 ). The bellows-seal gasket ( 20 ) and the profile ( 1 ) may be formed of plastic material in a single piece or fitted together.

[0001] The present invention relates to an improved sealing assembly forrefrigerator cabinets and the like with a profile made of plasticmaterial.

[0002] It is known from the Italian Patent No. 1281660 held by thepresent applicant, a profile made of plastic material for refrigeratorcabinets and the like, where the said refrigerator cabinets are equippedwith a door and an inner door panel constrained to the structure, saidprofile having a bellows-type gasket portion which provides a sealedclosing between the door and the cabinet. In this embodiment, theprofile and the gasket portion are coupled together or form a singleintegrated piece produced by co-extrusion of two materials havingdifferent degrees of rigidity so as to enable, if necessary, convenientdetachment of the gasket portion from the profile along the area oftheir connection. In addition, the profile has at least one elasticallycompliant side branch which acts as a spring to connect together by snapaction the profile and the inner door panel. In the aforesaid profile, agroove is present which is identified by a pair of walls that extendvertically or obliquely from a base which, in the operative position ofcoupling, overlaps the door and the inner door panel along their line ofcoupling.

[0003] For its installation, the profile, which carries the co-extrudedgasket, is conveniently arranged in the form of a frame and is suppliedto the manufacturer of the refrigerator cabinet in this form. As furtherreferences to the prior art, the following European patents held by thepresent applicant may be cited: EP 0 146 994 and EP 0 319 087.

[0004] The frame made of the profile is caused to descend, for exampleby means of an appropriate mechanical arm, towards the inner door panel,which is, for instance, suitably positioned on a support that blocks itin place. As soon as the arm of the side branch comes into contact withthe edge of the inner door panel, under the thrust of the said edge ityields and starts to bend elastically inwards like a spring about itsown flexible fulcrum. Once the compliant side branch has completed itstravel along the edge of the inner door panel and when the said edge hasreached the height of the above-mentioned groove, the branch, as aresult of its own elastic return, snaps into position engaging the edgeof the inner door panel, so blocking the said edge. Insertion of theframe welded on the inner door panel may be achieved with great easeeven manually, provided that care is taken to engage first the corners,two at a time, and then complete the insertion in the points of theperimeter where the edge of the inner door panel has not yet completelyentered the groove of the side branch.

[0005] The profile and the inner door panel thus assembled are thenrested on the door (for example, by means of a robotized system), andthe entire assembly is blocked by means of foam-injection into the gapbetween the door and the inner door panel, with functions of thermalinsulation.

[0006] In the profile in question, the base extends on a single plane oron planes that are slightly staggered with respect to one another. Thebase terminates laterally with a pair of sealing strips made of a softmaterial co-extruded together with the rigid material of the profile.The said strips constitute the gaskets containing the foam. Inparticular, the sealing strip provided to ensure operative sealing onthe inner door panel is made in such a way as to compensate for thedistance between the base of the profile and the inner door panelitself, between which there remains identified a gap for the elasticreturn of the engaging tooth of the side branch, and in such a way as tofacilitate the movement of engagement of the said branch on the innerdoor panel. The said sealing strip consequently also has the function offacilitating said movement of the side branch because it maintains thedistance between the base of the profile and the inner door panel,leaving free play for said engagement tooth in the useful gap referredto above.

[0007] It should in any case be emphasized that leakage of foam alongthe perimeter of the door is very rare, whereas it is precisely the areaof the corners where welding is carried out that proves particularlycritical.

[0008] It has in fact been noted that in the welded corner, the sidebranch, which terminates with a grooved seat, must remain elasticallymobile in order to guarantee functionality of the profile, andconsequently must not be welded. To avoid welding, the side branch mustbe cut 2-3 mm more than the cutting plane of the entire section of theprofile. Albeit preventing the branch from being welded, this solution,in the step of welding of the four sides of the frame, leads to thepresence of a 2-3 mm slit along the entire length of the side branch.

[0009] If the dimensional tolerances of assembly of the three componentsmaking up the door—namely, inner door panel, frame, and steel-metalshell—are not optimal, this slit leads to leakage of foam. In an attemptto prevent such leakage, the slit is closed with adhesive tape by meansof an operation that requires time and involves loss of productivity.

[0010] The purpose of the present invention is to further improvetightness of the seal to prevent any foam from leaking during the stepof foam-injection in a profile of the type referred to.

[0011] The above requirement derives from the fact that the parts to beassembled, and in the first place the profile and inner door panel, aremanufactured with dimensional tolerances that preferably tend to beincreasingly wide.

[0012] It should therefore once again be emphasized that the sealingstrip that extends from the base of the profile towards the inner doorpanel, as described in the Italian Patent No. 1281660 referred topreviously, proves in practice frequently insufficient to contain thefoam when the dimensional tolerances between the door and the inner doorpanel exceed a certain limit. This is especially true when the foam isinjected in the liquid phase according to the system known as “foamchamber” system, the said chamber being closed and inclined on itslonger side or on its shorter side. In this case, the liquid pours, infact, immediately onto the side opposite to the one into which the foamis injected, and the seal between the elastic side branch of the profileand the inner door panel may prove insufficient.

[0013] The fact that the foam comes out during the stage of foaminjection between the door and the inner door panel may mean damage ofan aesthetic nature (the foam that comes out is visible), but, aboveall, serious functional damage (the foam that leaks through the passageson account of insufficient sealing solidifies and causes seriousimbalance in the set of the assembled door-inner door panel system).

[0014] The solution to the technical problem summarized above isafforded by the present invention by means of an improved sealingassembly for refrigerator cabinets and the like with a profile made ofplastic material, as specified in claim 1.

[0015] Further salient characteristics and details of the presentinvention form the subject of the dependent claims.

[0016] The characteristics and advantages of an improved assembly forrefrigerator cabinets and the like with a profile made of plasticmaterial according to the present invention will emerge more clearlyevident from the ensuing description, which is provided by way ofnon-limiting example illustrating embodiments and practicalimplementation, with reference to the attached figures, in which:

[0017]FIG. 1 is a schematic perspective view of a refrigerator cabinetwith a door and inner door panel to which a profile is applied to makeup a sealing assembly according to the invention;

[0018]FIG. 2 is a cross-sectional view of the said assembly with theprofile in the operative position of assembly on the door and inner doorpanel, the section being taken along the line II-II of FIG. 1;

[0019] the pair formed by FIGS. 3 and 4 shows a detail of the embodimentof the assembly illustrated in FIG. 2 in two different operativepositions;

[0020] the two pairs formed by FIGS. 5 and 6 and by

[0021]FIGS. 7 and 8 show two further embodiments of the assemblyaccording to the invention in similar operative positions; and

[0022] the remaining FIGS. 9 and 10 show, instead, the action contrastof the sealing strip with the inner door panel for different radiuses ofcurvature.

[0023] With reference to FIG. 1, an improved sealing assembly forrefrigerator cabinets and the like with a profile made of plasticmaterial according to invention is shown. In this assembly, a profile isprovided, designated as a whole by 1. The profile 1 is operativelymounted between a door 30 and an inner door panel 31, and has a complexsection which presents, on the side facing, in the operative position(FIG. 2), a cabinet 32 of a refrigerator, a base 3 which issubstantially plane and extends on planes that are slightly staggeredwith respect to one another. The base 3 terminates, on a side part, witha sealing strip 15 and, on the opposite part, with a sealing strip 4,both of the said sealing strips being made of soft material co-extrudedwith the rigid material of the profile 1. In an intermediate position,the section of the profile 1 assumes an irregular T shape as a result ofa central rib 18 which extends vertically in the direction opposite tothe direction facing the cabinet 32, assuming a slightly angledconformation inwards. From the end of the aforesaid rib 18 there extendsa side branch 7, which is elastically compliant like a spring about afulcrum 8 consisting of an insert made of soft material co-extruded withthe rigid material of the profile 1.

[0024] The side branch 7 terminates with a grooved seat 19 having asubstantially C-shaped cross-section which includes a tooth 41 designedfor hooking onto the inner door panel 31.

[0025] In the opposite part of the profile 1, namely the one facing thecabinet in the operative position, there extend, from the base 3 in asubstantially vertical direction, a pair of walls 5 terminating with aflanged edge 5′, within which there thus remains identified a groove 23designed to receive a replacement gasket.

[0026] In the example of FIG. 2, the aforesaid vertical walls 5 are alsoslightly inclined in the same direction so as to be oblique andparallel. Alternatively, they could be oblique but divergent, or elsenot be inclined. In the operative position of coupling as illustrated inFIG. 2, the base 3 of the profile 1 overlaps the door and inner doorpanel, on which it forms a seal with the above-mentioned sealing strips4 and 15, respectively.

[0027] The profile 1 is made of rigid plastic material, for example PVC,which is extrusion-moulded, cut and welded to the corners in the form ofa frame that reproduces the perimeter of the door of the refrigeratorcabinet to which it is to be applied.

[0028] Moulded together with the profile 1, by co-extrusion, so as toform a single piece, is also a gasket 20, for example made of softplasticated PVC. The said gasket 20 has a tubular section whichidentifies an extensible chamber 21 that functions as a bellows, and atop chamber 24 that runs alongside a seat 22 designed to receive a barof magnetic material, represented schematically and designated by 27. Aninternal side wall, designated by 6, of the gasket 20 is welded to thecorresponding wall 5 of the profile in the point of co-extrusion 13,whilst an external side wall, designated by 16, is welded in an integralway to the corresponding external wall 5 of the profile and along theexternal side of the base 3.

[0029] As mentioned above, the side branch 7 of the profile operativelyfacing the inner door panel terminates with a grooved seat 19 having asubstantially C-shaped cross-section. As is more clearly highlighted inFIGS. 3 to 8, the said C-shaped section comprises, in addition to thetooth 41 referred to above, also a bottom side 9 designed for resting ofthe inner door panel in the operative stage, as illustrated in FIG. 4 orFIG. 6.

[0030] In a first embodiment of the profile, illustrated in FIGS. 2, 3and 4, in the grooved seat 19 having a C-shaped cross-section a sealingstrip 2 made of soft co-extruded material is provided along the end ofthe tooth 41. In the two variants illustrated by the pairs of FIGS. 5-6and 7-8, the sealing strip 2 is set in different points of theabove-mentioned C-shaped cross-section. In particular, in the embodimentof the profile illustrated in FIGS. 5 and 6, the sealing strip 2 ismade, at the bottom, in an intermediate point of the tooth 41, whilst inthe embodiment of the profile illustrated in FIGS. 7 and 8, it is madeon the bottom side 9 of the C-shaped cross-section. In a differentembodiment of the profile, in an assembly according to invention notshown in the attached drawings, two or more sealing strips may beprovided in different points of the same seat 19 having a C-shapedcross-section.

[0031] The sealing strip 15 is made, above all, so as to compensate forthe distance between the base 3 of the profile and the inner door panel31, between which there remains identified a gap 40 for the elasticreturn of the tooth 41 of the side branch 7, and so as to facilitate themovement of engagement of said side branch 7 on the inner door panel.

[0032] The sealing strip 15 has the function of facilitating saidmovement of the side branch 7 because it maintains the distance betweenthe base of the profile and the inner door panel 31, leaving free playfor the tooth 41 in the gap 40. The sealing strip 15 moreover hasfunctions of an aesthetic nature because it covers from sight theunderlying rigid profile, which can be made of any shade of colour,without this being detrimental to the appearance of the assembly.

[0033] In order to solve the technical problems of leakage of foam, ithas moreover been found that an area of bending, designated by 29, ofthe inner door panel 31, must be at right angles and must have a radiusof at least 3 mm up to a maximum of 6 mm. In this way, it is possible toensure an optimal action of contrast with the sealing strip 15 made atthe end of the base 3 of the profile 1. As a result, an effective andsecure sealing action against the inner door panel is achieved,preventing any leakage of foam.

[0034]FIG. 2 shows how a radius of bending of 5 mm is used, whilst thelast two FIGS. 9 and 10 show the action of contrast of the sealing strip15 with the inner door panel for different radiuses of curvature. It mayreadily be imagined that with a radius of 3 mm (FIG. 9) the contrast issomewhat deficient, whereas with a radius of 6 mm (FIG. 10) it is,perhaps, excessive. A good action of contrast, and hence a good seal,against leakage of foam is obtained when the radius of bending of theinner door panel is between the aforesaid two limits. It is to beconsidered that all of the inner door panels currently used have in thatpoint a radius of bending of 1.5 to 2 mm.

[0035] The above solution moreover makes it possible to keep the sealingstrip 15 of a length such as it does not prevent rotation of the sidebranch 7 with the grooved seat 19. The radius mentioned above ensures agood action of contrast between the sealing strip 15 and the inner doorpanel even in sub-optimal conditions of tolerance between the componentsof the door.

[0036] For installation, the profile 1 carrying the co-extruded gasket20 is conveniently prepared in the form of a frame, and in this formsupplied to the manufacturer of the refrigerator, as described in theEuropean patents held by the present applicant already cited above.Coupling of the above frame to the inner door panel may be obtainedeither manually or using a robotized system. If the operation is carriedout manually, it is necessary to push the perimetral edge of the innerdoor panel against the compliant side branch, first in the corners andthen in the perimetral points.

[0037] If a robotized system is used, the frame formed with the profile1 is made to descend, for example by means of an appropriate mechanicalarm, towards the inner door panel 31, which is, for instance, suitablypositioned on a support that blocks it in place. As soon as the arm ofthe side branch 7 (in the initial position indicated by the dashedoutline 7′ in FIG. 2) comes into contact with an end edge 28 of theinner door panel 31, under the thrust of the said edge it yields andstarts to bend elastically inwards like a spring about the fulcrum 8,which is in fact flexible. Once the compliant side branch 7 hascompleted its travel along the edge of the inner door panel 31 and whenthe said edge has reached the height of the groove 19, the branch 7, asa result of its own elastic return, snaps into position and engages theedge 28 of the inner door panel 31, so blocking the said edge.

[0038] In the embodiment of FIGS. 2, 3 and 4, it may therefore be seenhow the movement of approach and co-operation between the inner doorpanel 31 and the side branch 7 leads the sealing strip 2 to assume, inthe final operative position, the conformation shown in detail in FIG.4.

[0039]FIGS. 6 and 8 illustrate the final operative positions of thesealing strip 2 of the two further embodiments shown in the drawings.

[0040] In any case, the aforesaid final operative positions show that,under the action of elastic return of the side branch 7, the sealingstrip 2 is always compressed against the edge of the inner door panel31, so that, in this way, an excellent seal is obtained.

[0041] In fact, the profile 1 and the inner door panel 31 thus assembledare then rested on the door 30 (for example, by means of a robotizedsystem), and the entire assembly is blocked by foam-injection into thegap between the door and the inner door panel. Preferably, acounter-mould is positioned on top of the door and inner door panelassembled together with the frame of the profile of the assemblyaccording to the invention in such a way as to exert an adequatecounter-thrust against the pressure of the foam material which isinjected inside the gap defined between the door and the inner doorpanel in order to provide thermal insulation.

[0042] Prevention of leakage of foam is ensured by the action ofcontrast between the sealing strip 15, bent to form an L, of the baseand the area of bending at right angles 29, of the inner door panel 31,which has a radius of curvature of between 3 and 6 mm.

[0043] The sealing strip provided in the grooved seat of the side branchaccording to the invention is such as to guarantee a sort of sealagainst a possible leakage of foam between the inner door panel and theprofile because the said sealing strip does not merely function as aso-called “static seal”, i.e., one obtained by mere resting and contactbetween the parts in the possible points of leakage of the foam, butoperatively works by compressing itself against the edge of the innerdoor panel, thus deforming its own structure and so providing a seal ofconsiderable and certain effectiveness.

[0044] Also the sealing strip 15, in order to create a seal on the innerdoor panel part with a radius of 3 to 6 mm, is compressed, partially ortotally deforming the vertical branch of the L.

[0045] It may therefore be seen how the main purpose initially set,namely that of being able to guarantee sealing of the foam in the pointsof widest dimensional tolerance in the door-inner door panel assembly iseffectively achieved by means of the assembly proposed by the presentinvention.

[0046] Optimization of the seal against leakage of foam is obtainedessentially thanks to the pressure of the sealing strip 2 made of softmaterial co-extruded at the end of the tooth 41 of the grooved seat 19having a C-shaped cross-section, and by the sealing strip 15 having areversed L shape positioned at the end of the base 3 in the area ofbending at right angles 29, of the inner door panel 31, which has aradius of 3 to 6 mm.

1. An improved sealing assembly for refrigerator cabinets and the likewith a profile made of plastic material, where said assembly is made upof a cabinet (32), a door (30), and an inner door panel (31), which canbe coupled to the cabinet (32), and a portion of bellows-type gasket(20) which provides sealed closing between the door (30) and the cabinet(32), it being envisaged that a profile (1) and said portion of gasket(20) are fitted together or form a single integral piece produced byco-extrusion of two materials having different degrees of rigidity, soas to enable, if necessary, convenient detachment of the portion ofgasket (20) from the profile (1) along the area of their connection,said profile (1) having a groove (23) designed to receive a replacementportion of bellows-type gasket, and at least one elastically compliantside branch (7) which acts to provide snap-action connection between theprofile (1) and the inner door panel (31), said branch (7) terminatingwith a grooved seat (19) which has a substantially C-shapedcross-section and is designed to receive an edge (28) of said inner doorpanel (31), it further being envisaged that said profile (1) has a base(3) provided, at opposite ends, with sealing strips (4, 15) whichco-operate with said door (30) and said inner door panel (31),characterized in that, in said grooved seat (19) having a substantiallyC-shaped cross-section, at least one sealing strip (2) is provided thatis made of soft material and is set facing said edge (28) of the innerdoor panel (31), so that when said inner door panel (31) is operativelyconnected to said profile (1), under the action of elastic return ofsaid branch (7) said sealing strip (2) is compressed against the edge(28) of said inner door panel (31), it further being envisaged that anarea of bending at right angles (29) of said inner door panel (31) has aradius of 3 to 6 mm so as to ensure an optimal action of contrast withone (15) of said sealing strips of said base (3) of said profile (1). 2.The sealing assembly according to claim 1, characterized in that saidsealing strip (2) is co-extruded with said profile (1).
 3. The sealingassembly according to claim 1, characterized in that said sealing strip(2) is set along the end of said seat (19) having a C-shapedcross-section.
 4. The sealing assembly according to claim 1,characterized in that said sealing strip (2) is set inside said seat(19) having a C-shaped cross-section.
 5. The sealing assembly accordingto claim 1, characterized in that said sealing strip (15) is made ofsoft material co-extruded with a rigid material of said base (3) of saidprofile (1).
 6. The sealing assembly according to claim 1, characterizedin that in said profile (1) said groove (23) is identified by a pair ofwalls (5) that extend either vertically or obliquely from a base (3)which, in the operative position of coupling, overlaps the door (30) andinner door panel (31) along their line of coupling.
 7. The sealingassembly according to claim 1, characterized in that in said side branch(7) a fulcrum (8) of the spring is constituted by an insert of asubstantially soft material formed in the substantially rigid materialof which the profile (1) is made.
 8. The sealing assembly according toclaim 1, characterized in that said gasket (20) is co-extruded with saidprofile so as to overlap the latter along the entire length of theoperatively external one of said pair of walls (5), and so as to overlapthe portion, which is also external, of said base, in such a way as tohide from sight the profile in the operative position.
 9. The sealingassembly according to claim 1, characterized in that said base (3) iscontained in a single plane.
 10. The sealing assembly according to claim1, characterized in that said base (3) is contained in planes that areslightly staggered with respect to one another.